Time zone lines and suicides: west side story
A recent study (1) specifically finds high serotonin loadings in the brain of patients who attempt violent suicide. This is important because it connects to a previous area of research (2) showing that the human brain produces more serotonin when exposed to sunlight for longer periods of time. These two studies jointly suggest that the longer the exposure to sunlight, the higher the concentration of serotonin, and thus the more likely a patient is to attempt suicide. The extent to which sunlight exposure contributes to suicide has long been debated. On the one hand, lack of sunlight during the winter season is linked to seasonal affective disorder, and perhaps suicidal depressive moods (3). On the other hand, suicides peak in the spring and summer months (2) and midday rather than nighttime (4).
Quercioli, E. (2012), Time zone lines and suicides: west side story. Acta Psychiatrica Scandinavica, 126: 153-154. https://doi.org/10.1111/j.1600-0447.2012.01893.x
Acta Psychiatrica Scandinavica